#include "keyboard.h"
#include "print.h"
#include "interrupt.h"
#include "../lib/kernel/io.h"
#include "global.h"


#define KBD_BUF_PORT 0x60

/* 用转义字符定义部分控制字符 */
#define esc		'\033'	 // 八进制表示字符,也可以用十六进制'\x1b'
#define backspace	'\b'
#define tab		'\t'
#define enter		'\r'
#define delete		'\177'	 // 八进制表示字符,十六进制为'\x7f'

/* 以上不可见字符一律定义为0 */
#define char_invisible	0
#define ctrl_l_char	char_invisible
#define ctrl_r_char	char_invisible
#define shift_l_char	char_invisible
#define shift_r_char	char_invisible
#define alt_l_char	char_invisible
#define alt_r_char	char_invisible
#define caps_lock_char	char_invisible

/* 定义控制字符的通码和断码 */
#define shift_l_make	0x2a
#define shift_r_make 	0x36 
#define alt_l_make   	0x38
#define alt_r_make   	0xe038
#define alt_r_break   	0xe0b8
#define ctrl_l_make  	0x1d
#define ctrl_r_make  	0xe01d
#define ctrl_r_break 	0xe09d
#define caps_lock_make 	0x3a

/* 定义以下变量记录相应键是否按下的状态,
 * ext_scancode用于记录makecode是否以0xe0开头 */
static bool ctrl_status, shift_status, alt_status, caps_lock_status, ext_scancode;

/* 以通码make_code为索引的二维数组 */
static char keymap[][2] = {
/* 扫描码   未与shift组合  与shift组合*/
/* ---------------------------------- */
/* 0x00 */	{0,	0},		
/* 0x01 */	{esc,	esc},		
/* 0x02 */	{'1',	'!'},		
/* 0x03 */	{'2',	'@'},		
/* 0x04 */	{'3',	'#'},		
/* 0x05 */	{'4',	'$'},		
/* 0x06 */	{'5',	'%'},		
/* 0x07 */	{'6',	'^'},		
/* 0x08 */	{'7',	'&'},		
/* 0x09 */	{'8',	'*'},		
/* 0x0A */	{'9',	'('},		
/* 0x0B */	{'0',	')'},		
/* 0x0C */	{'-',	'_'},		
/* 0x0D */	{'=',	'+'},		
/* 0x0E */	{backspace, backspace},	
/* 0x0F */	{tab,	tab},		
/* 0x10 */	{'q',	'Q'},		
/* 0x11 */	{'w',	'W'},		
/* 0x12 */	{'e',	'E'},		
/* 0x13 */	{'r',	'R'},		
/* 0x14 */	{'t',	'T'},		
/* 0x15 */	{'y',	'Y'},		
/* 0x16 */	{'u',	'U'},		
/* 0x17 */	{'i',	'I'},		
/* 0x18 */	{'o',	'O'},		
/* 0x19 */	{'p',	'P'},		
/* 0x1A */	{'[',	'{'},		
/* 0x1B */	{']',	'}'},		
/* 0x1C */	{enter,  enter},
/* 0x1D */	{ctrl_l_char, ctrl_l_char},
/* 0x1E */	{'a',	'A'},		
/* 0x1F */	{'s',	'S'},		
/* 0x20 */	{'d',	'D'},		
/* 0x21 */	{'f',	'F'},		
/* 0x22 */	{'g',	'G'},		
/* 0x23 */	{'h',	'H'},		
/* 0x24 */	{'j',	'J'},		
/* 0x25 */	{'k',	'K'},		
/* 0x26 */	{'l',	'L'},		
/* 0x27 */	{';',	':'},		
/* 0x28 */	{'\'',	'"'},		
/* 0x29 */	{'`',	'~'},		
/* 0x2A */	{shift_l_char, shift_l_char},	
/* 0x2B */	{'\\',	'|'},		
/* 0x2C */	{'z',	'Z'},		
/* 0x2D */	{'x',	'X'},		
/* 0x2E */	{'c',	'C'},		
/* 0x2F */	{'v',	'V'},		
/* 0x30 */	{'b',	'B'},		
/* 0x31 */	{'n',	'N'},		
/* 0x32 */	{'m',	'M'},		
/* 0x33 */	{',',	'<'},		
/* 0x34 */	{'.',	'>'},		
/* 0x35 */	{'/',	'?'},
/* 0x36	*/	{shift_r_char, shift_r_char},	
/* 0x37 */	{'*',	'*'},    	
/* 0x38 */	{alt_l_char, alt_l_char},
/* 0x39 */	{' ',	' '},		
/* 0x3A */	{caps_lock_char, caps_lock_char}
/*其它按键暂不处理*/
};

struct ioq kbd_buf;


static void intr_keyboard_handler(){
    bool ctrl_down_last = ctrl_status;
    bool shift_down_last = shift_status;
    bool caps_lock_last = caps_lock_status;  

    bool break_code;
    uint16_t scancode = inb(KBD_BUF_PORT);

    if(scancode == 0xe0){
        ext_scancode = true;  // 标记为ext 
        return;
    }

    if(ext_scancode){
        scancode |= 0xe000;
        ext_scancode = false; // 清除标记ext 
    }

    break_code = (scancode & 0x0080) != 0;  // 松开按键
    
    if(break_code){ // 是break_code
        uint16_t make_code = (scancode &= 0xff7f); // 规定
        switch(make_code){
            case ctrl_l_make: case ctrl_r_make: ctrl_status = false; break;
            case alt_l_make: case alt_r_make: alt_status = false; break;
            case shift_l_make: case shift_r_make: shift_status = false; break; 
        }
        return;
    } 
    
    // 不是break_code， 是字。如果不是shift：
    else if ( (scancode > 0x00 && scancode < 0x3b) || (scancode == alt_r_make)|| (scancode == ctrl_r_make) ){
        bool shift = false;
        if( (scancode <  0x0e) // 0-9, '-', '='
         || (scancode == 0x29) // '`'
         || (scancode == 0x1a) // '['
         || (scancode == 0x1b) // ']'
         || (scancode == 0x2b) // '\\'
         || (scancode == 0x27) // ';'
         || (scancode == 0x28) // '\''
         || (scancode == 0x33) // ','
         || (scancode == 0x34) // '.'
         || (scancode == 0x35) // '/'
         ){ if(shift_down_last) { shift = true; } }  // shift没有回弹
        else{
            if(shift_down_last && caps_lock_last){ shift == false; }  // 同时有capslock和shift键，不大写     
            else if(shift_down_last || caps_lock_last ) { shift = true; }  // 有其中之一
            else { shift = false; } // 都没有，不大写
        }

        uint8_t index = (scancode &= 0x00ff);
        char cur_char = keymap[index][shift];
        if(cur_char){  // cur_char != 0, printable
            
            if(!ioq_is_full(&kbd_buf)){
                // put_char(cur_char);
                ioq_put_char(&kbd_buf, cur_char);
            }
            
            return; 
        }

        switch(scancode){
            case ctrl_l_make: case ctrl_r_make: ctrl_status = true; break;
            case alt_l_make: case alt_r_make: alt_status = true; break;
            case shift_l_make: case shift_r_make: shift_status = true; break;
            case caps_lock_make: caps_lock_status = !caps_lock_status; 
        }
    }

    else {  put_str("[unhandled key]");  }
}

void keyboard_init(){
    put_str("keyboard init start\n");
    register_handler(0x21, intr_keyboard_handler);
    put_str("keyboard init done\n");
}





